Of Service to you, Professional Engineering Opinion on AGM vrs Lithium

[Helia 44]

LATEST UPDATE AGMS VRS LITHIUM, My Professional Engineering study for my SABA 50 Cat.... I am in Australia, not selling anything, this is to help you know and understand the real issues of Lithium being cost effective. My Engineering Study is in three parts here for your benefit.

Hello Friends, here is the problem. Not money problem for me, not that LIthiums are not better, not that they are not lighter, not that they do not perform better... It is just too much of massive job, and here is an outline of why.

I (my Staff) have put in more than 500 Lithium systems up to 900 AH in mobile settings in the Outback. Trust me I am a Lithium Expert, to coin a label...

Now, Amateur Lithium installations without all the safeguards necessary, kills the Lithium batteries in about the life time of normal AGM batteries. You need to have proper charging systems in the right algorithm, solar regulators in the correct algorithm, my Victron combi Inverter Chargers would need modifications or reprogramming, you need LVD Low Voltage Disconnects so they cannot be accidentally abused, and you need the proper BMS Battery Management System for each Lithium battery so the cells all equalize or you start to devalue the system into failure. Now a lot of people that sell the Lithium can do all that, and some of the higher quality Lithium 100 AH to 200 AH batteries have the BMS on board... However, it all goes a lot deeper if you want the Lithium to last long enough to be cost effective:

I am writing this to be of Service to you my Friends, and tell you what I am doing because of it all.. Now the next layer is the engines alternators. You have to have a buffer AGM style starting battery, and then DC to DC chargers on each engine in the proper Lithium algorithm (proper charging curve for Lithium) or you grossly cut their life in half to maybe only five years like AGMs.. But then again some people get 8 years out of AGMs) Anyway besides the wiring in of DC to DC charger in the Lithium algorithm, these type of chargers cannot run all the time, they have to be ignition relay tripped to start. Still there is more: All the Lithiums that do have BMS on each battery (most quality ones that are not just gimmick sales) when you put these commonly sized 100-200 AH batteries together, the individual BMS systems are not enough. You have to have an overall BMS type system over all the batteries, called Active Balancing. It works just like the individual battery systems BMS, levelling up the charge, equalising the cells, but on the overall system. It treats all the batteries like bigger cells, and keeps them equalised in all the charging systems. Failure to have this overall Active Balancing BMS style system as well, means eventually one battery in parallel, will go down and not recover and kill the rest in a slowly failing system.

But Wait, there is more!! Heh he.. You have to also have an overall Metering system like Victron, that tells you the state of charge, but also regulates when the batteries are being charged and by how much. Without this system you would have to be an Attendant doing it all manually and that is nearly impossible. You have to have like an Enerdrive or Victron battery management meter, that trips something like Blue Sea Relay drivers, to run the LVD and all the charging systems so you do not continually charge or undercharge the system. Both again will cut the Lithium Life in half... You cannot keep charging the Lithium after it is fully charged, the overall Meter has to regulate all the charging systems or again you shorten the life of the Lithiums..

I am telling you this, because I am in the Business, and to get a 1000 AH system to run something like the Saba 50, is a massive expenditure like $18,000- $20,000 Aus in Lithium and equipment, and a week to ten days of solid work by a qualified Technician wiring everything i properly or the system will not pay off with long life... We are about 12 months backed up on Orders, I cannot pull one of my Electrical Technicians off for a week-ten days to redo my yachts whole charging systems.. After careful consideration: I am staying with AGMs

Long and the short of it, since the extra 150 kg of weight does not bother the Saba, I am thinking I am going to just stay AGM batteries. I can replace them all for about $3000 (Aus) in over 1000 AH total, like the original Varta batteries. The design of all the equipment is already there to maintain them properly. My German Varta batteries are now about six years old, and I am only doing this now because of anticipated Covid supply disruptions.. It is a pre-emptive move. My point for you is, you can buy four sets of AGM batteries for the cost of the Lithium. And while yes the Lithium outperforms, IMO in my case not worth the expense and hassle. I have an 11 kva Cummins Onan now six years old and only has 604 hours on it.. And the Lithium system has to work flawlessly to make itself cost efficient. Other than the weight factor in our case in the Outback in mobile applications it is not necessarily worth the expense.

I am thinking I am going to buy four 280 AH AGM big trawler type batteries instead. You do what is best for you. The Lithium outperforms but at several times the cost without the proper management systems I have outlined above for you, they are expensive and not going to last long enough to be cost effective. This post was in "Your Best Interests"

Skipper Owner on Saba 50 "Serenity", getting ready to live at anchor during the Covid Plague likely to get out of hand next year in Australia as Lockdowns are quit.. Lockdowns banckrupt the country, threaten to topple Governments in Australia, and the Population little affected in the 20-40 year old range start to demonstrate and protest and riot.. Just like Europe.. Australia IMO is likely to follow the Euro pattern and go grim reaper ending lockdowns..

Good luck to all of you and God Bless....

READ ON, PART TWO AND THREE OF STUDY TO FOLLOW THIS POST.....

[Helia 44]

Addendum to the above Post on going AGM or Lithium batteries on the Saba: Part two of my week of dilemma here for your best interests:

My Lithium Battery choice was the Enerdrive 300Ah Compact Pro Series Lithium Battery. This is in a powder coated case, with some higher end features, the best made IMO... Enerdrive "Top of the Line"...

Now this is 50 kg each, so three of them 150 kg. The 280 Amp Hour AGMs are 62 kg each, for of them 248 kg. In summary: In this case, on a Saba 50, it is less than 100 kg more.

YES the Lithium will charge easier, YES the Lithium will charge faster, YES they will accept solar easier. YES, I would get about 60% more out of the Lithium in useable power.. I have proven all of that. However, it is a massive undertaking on the Saba as there would have to be massive modifications done to all the equipment and about a week to ten days for an Electrical Technician to add all the equipment, new solar regulators, new DC to DC chargers, separate starting batteries for the engines, Victron Combi Inverter charger modifications, and more.

In short, in my Professional Opinion, when I have two generators and my main generator is a Cummins Onan with only 604 hours in six years, on what is probably a 10,000 hour or more unit, I am going the AGMs. Yes it will take longer to charge my batteries on the Cummins Onan, but we run big water maker and air conditioning is the hot spells anyway. If everything went perfect the Lithium could last longer, but at four times the cost of the AGMs and a week to ten days of a Technician, IMO it is not worth the effort and not cost effective. Not only that, but Enerdrive are estimating 1600 cycles or more, and the AGM Company is saying 1600 as well. So, it comes down to a little more diesel, or four times the cost after the Technician about 5 times the cost??? The SABA will not notice the extra weight.

With the added starting battery on the D2-75's, and DC to DC chargers, the weight difference is probably only 80 kg, so throw that one out the window two... Five times the cost to do it properly, I have decided to stick with the AGMs... And I am well into the Lithium Business in the mobile applications.

FINAL NOTE: If I was building the SABA from scratch, I would go the Lithium batteries and charging systems WITHOUT A DOUBT. But to convert over all the extensive systems on the Saba now, with all the added cost of doing it retroactively? I just do not think it worth the extreme expense and effort.

"In your best Interests" Skipper/Owner Saba 50 "Serenity"..

[Helia 44]

PART THREE OF THE THIS ENGINEERING STUDY...

COMPLETE REVERSAL.... Per the previous two posts on AGM / LITHIUM Engineering.. I am going the full big Lithium System.... Why the reversal?

On my final system design engineering study, the generator run time to get the full Boost Cycle on the AGM batteries, is just too long. Without the Boost cycle to clean the plates and do full equalisation at least every week or so they will not last that long.. So, my Covid 19 living at anchor if need be: Prep is to go the full Lithium system, as I expect it rage in Australia next year like Europe and America... I am anticipating weathering it living at anchor.. IMO We cannot afford the Lockdowns here, economic bankruptcy, social unrest and demonstrations, and Political revolt is overcoming the mandated lockdowns...

My Lithium Battery choice is the Enerdrive 300Ah Compact Pro Series Lithium Battery. This is in a powder coated case, with some higher end features, the best made IMO... Enerdrive "Top of the Line"... We have maybe 400-500 in the field in mobile settings in the Outback of Australia..

YES the Lithium will charge easier, YES the Lithium will charge faster, YES they will accept solar easier. YES, I would get about 60% more out of the Lithium in useable power.. I have proven all of that. However, as I stated in the previous two posts, it is a massive undertaking on the Saba as there would have to be massive modifications done to all the equipment and about a week to ten days for an Electrical Technician to add all the equipment, new solar regulators, new DC to DC chargers, separate starting batteries for the engines, Victron Combi Inverter charger modifications, and more. Not to do the whole job of it, would mean an early death to the Lithiums and at four times the cost not worth putting them in as not cost effective IMO.

Notes on the final Systems Engineering design: I am putting in a 3kw Victron Combi Unit, 120 amp charger, 3000 watt inverter.. I will have the 60 amp and 80 amp Victron Combi units as spares or for another project. They are not ready for the Lithium system algorithm and would conflict with each other if modified. I also have to have the Pro Compact 300 AH Lithiums BMS modified on each one, to run three of them under a general BMS sort of system called Active Balancing so they do not get out of sync..

I will be leaving one Varta Euro Pro AGM 150 AH on for each engine. They are still good, and store the other five at home on a timer charge and run them out. They are so big and the Volvo D2-75s start so easy, it is not much of a discharge on the big Varta 150s even though they are Deep Cycle and not meant for starting batteries it is not much of a jolt. And: I get some extended use out of them even though 6 years old. I would not be doing this, but they are going to lift all travel restrictions for the Christmas School Holidays in Australia so I expect the Covid-19 to come raging on here by April May our Fall down under, going into winter.. I anticipate living at anchor up in the Islands of the Great Barrier Reef, so three things will be important: Lithium, Lithium, and Lithium. It is going to be an expensive system, but I think the investment well spent and it probably will increase the value of the Saba as much or more. It will be about a $20,000 (Aus) system.

In addition to the Victron Lithium algorithm Combi unit, there will be a DC to DC charger in Lithium algorithm off each engine starting battery. These Volvo alternators are $1000 each here in Australia, and the onboard regulator is not available. In Lithium, they would probably be twice as much and also not available in Australia. Sooooo, this cost may not be there for you in the USA. But here, the starting battery is designed to be a buffer, and the DC to DC chargers will come off of that. I will also have two Epro 60 amp chargers in the Lithium algorithm as backup, wired in, to run off the Generator.

Finally there has to be the top end TPS type Victron style Battery Meter BMS installed. It will be programmed to run a couple of Blue Sea type relays to regulate the charge on and off as needed, and an LVD Low Voltage Disconnect safety system and so on. You need this system not for the readout of state of charge and so on, you need it to start and stop the charging cycle so you do not abuse the Lithiums. All in all this is a very up market system, but it is necessary or you run the Lithiums to an early demise.. The Professional Grade Lithiums 300 AH in powder coated armour cases run about $A 4000 each so you want them to last... I would hope ten years..

If you just do the average Lithium battery install without all the right BMS and Active Balancing and the rest, you would be lucky to get five years out of them. In that case you might as well stay with AGM style batteries at about 1/4 the cost, like 1/10th the cost with your stock AGM charging systems not having to be modified or replaced.

You can take this as the latest Professional advice. My Company has done maybe 500? Lithium installations in mobile units for the Outback, and we only do it properly with the latest technology. I am not for hire, not selling anything, and I hope this has been a help for you Free of Charge.

Kind regards, Skipper, Saba 50 "Serenity"...... And God Bless...

[jmh2002]

Since you are designing everything from scratch have you given some thought to having two smaller inverters (maybe even with a higher combined total kW rating) running in parallel instead of one big inverter from a redundancy point of view?

Perhaps it is not as necessary since you have the generator, and as a tech replacing an inverter is less daunting than for the average cruiser, but the convenience of automatically (or manually) being able to immediately continue running on the one good inverter sounds very attractive from a cruising perspective.

My two cents...

[Helia 44]

I have two Victron Combi units on board now, one with 80 amp charger, one with 60 amp... They both are combi charger/inverters, both have remotes, to run charger only or both charger and inverter, or off..

Works fine... But they are 5-6 years old and will not interface well on the Lithium charging algorithm somewhat cancelling each other out on the charging mode..
I could get them to interface, shipping back to Victron, Melbourne 2000 kms away, and converted to Lithium. But I have elected to keep them as spares and go new. They would not interface well so I am told, and would need extensive mods, so with shipping and everything I decided it was more cost effective you keep them for other uses and buy new Enerdrive 3 kw Combi unit which have proven to be amazingly reliable at cost due to my Business connections. It just suits this demographic area, either way would be roughly the same cost probably. This is what I am doing, but useless advice for you.

I may modify one, maybe the larger Victron Combi, ship it to them and keep it as a spare. I have two remotes, so can leave the one in place for the 80 amp Victron, and put in a new remote for the 3 kw.

This advice is near useless. No one is likely to have this situation and it's fix is more unique to Australia. I have answered it for you, but it is just what I am doing. You need to talk with Victron and see about the interface unit that has to be added to run two Combi units, I like your redundancy idea, but don't know if it is necessary.

[George DuBose]

I have gotten 10-12 years out of my Optima Yellow Top Series 31s.

Recently, I replaced three of the Optimas with Full River Series 31s and I am curious to see how they last.

With the three Optimas in the house bank, they had been "flattened" three times in 10 years, usually due to a disconnect with shorepower. I was interested in desulphating them and bought a BatteryMinder battery charger that is supposed to dislodge the sulphate with frequencies. It actually seemed to work and I was able to get several more years from them.

The expense of Lithium and the fact that I use my engine quite often when cruising leads me to want to stick to diesel power and batteries that I can afford.

[hzcruiser]

No offense, but it's a bit difficult to follow this writing style... too long and repetitious for most, I'd say.

Regarding equalizing several LFP batts I don't really see how or why that's needed, maybe someone can support that with links to other sources? I deliverately run different size LFPs in different spots on the boat, partly for testing, partly because I want the power storage closer to the respective consumers.

[contrail]

Before you make that complete U Turn, based on the fact that your AGM batteries disqualify themselves due to needing some care when in Partial State of Charge operation, have you researched Firefly Carbon Foam AGM's, which handle PSOS use very differently and seamlessly? They don't need to be brought up to full charge on a weekly basis, and don't permanently sulfate, and can be operated to a lower state of charge. Might be worth a glance. One of the members of this forum, Bruce Schwab of Ocean Planet, is the professional guru on the Fireflys. Perhaps he will chime in. He is also a Lithium guy so you probably speak the same language as each other!

[waterman46]

Originally Posted by contrail

Before you make that complete U Turn, based on the fact that your AGM batteries disqualify themselves due to needing some care when in Partial State of Charge operation, have you researched Firefly Carbon Foam AGM's, which handle PSOS use very differently and seamlessly? They don't need to be brought up to full charge on a weekly basis, and don't permanently sulfate, and can be operated to a lower state of charge. Might be worth a glance. One of the members of this forum, Bruce Schwab of Ocean Planet, is the professional guru on the Fireflys. Perhaps he will chime in. He is also a Lithium guy so you probably speak the same language as each other!

PSOC operation of Firefly is outstanding, if really true.

But according to their website, Firefly carbon foam batteries come in only two sizes, one at 12V only 116AH and 4V at 450AH. Both sizes are rather strange to me, and would require extensive modifications to boats already having the more normal 4D or 8D, even some Group XX spaces, to fit the same AH capacity.

Can't understand the marketing decision for those unique sizes. Hope they will soon produce a 4D size and capacity should be 200AH, competitive on market at $750 (Lifeline 4D is about $600).

[PineyWoodsPete]

My '14 Greenline 33 Hybrid m/v has a 48V 240Ah/11.6kWh LiPo bank in a metal case, approx. 3.5x1.5' weighing 80kg. There's a water-cooled 48V 7/5kW motor/gen. in-line with the 165HP diesel, and a 500W solar array. The Victron 48V 5000W Multiplus Duo inverter/charge supplies full time 120V to all-elect. galley, HVAC, and maintains the four AGM's for starting, 12V house, and thrusters. It shows no signs of decreased capacity so far, and floats at 54.35V with less than 0.5A input on the Victron status monitor.

Yesterday I ran a "stress test" with the electric motor drawing ~120A/6kW for about 45 min. at 4.5-5kt - voltage from about 53.5 to 48 underway at end, rising to 49V with motor off. The manual cautions against dropping below 44V. Solar power controller doesn't kick in until below 52.8V, then off at 53.8. Battery photos with close-up of BMS below...

[BruceS]

"...500 installs in mobile settings in the outback..."
Care to elaborate a bit?
That big I'm guessing you have a pretty good website I can browse?
Sounds a bit like a chap who USED to be on here until his lights were switched off.

[Helia 44]

Just a couple of things to address here, then I am gone..

HZ Cruiser, You don't like my style of writing, don't read it, go away. This was a free Service to help others, and I gave it the way I analysed it over a week of review People in general absorb only 60% of what they see and 40% of what they hear. I have been educating them on extreme 4x4 travel in the Outback with my Company for 25 years, now retired. Yes Cruiser, this was meandering, as I went through the week of analysis in all the pros and cons to decide from an Engineering standpoint which way to go, I wrote what I was reviewing and why...

IN SUMMARY: Final Post on this. Yes Lithium is better, but not necessarily worth the cost to convert and do it right, unless you have money to burn. To do Lithium right, conversion of all the Charging systems, I mean I even have to change out my Solar Regulator, Going 60 amp Morningstar MPPT Regulator. Look to get 10 years maybe 15 years out of Lithium and do it all Professionally is a HUGE undertaking and NOT WORTH THE MONEY in my Professional Opinion and I have done more than most with 500 units working in the field as the technology improved.

The point is I am telling you the Professional Engineering of what is required to make Lithium cost effective. If you do not do it all correctly, and do the cheap shortcuts, if you do not do the whole enchilada as I have outlined, instead of 10-15 years and more out of Lithium, you will be lucky to get five years and almost all AGM battery systems will do that.

The point is from new, it would only be about three or four times the cost of AGM as all the equipment could be built from new just for the LIthium algorithm. But having to change over all the equipment is very costly....
In my Business, there is a 100 kg weight savings to Lithium over 4 house batteries. In the Transport Industry, many of my Owners are up on their upper weight limits.. So that thrown in and most go the Lithium.

This does not apply to my yacht. The ONLY reason I am going to Reverse my standing and go Lithium is the SARS-Cov-2 Pandemic, and I am planning to live at anchor most of the time if it comes back in Australia big time like the rest of the world.. Money no object if that happens and Lithium is better I also get all the equipment at wholesale and bigger discounts as I am in the Business. I can afford it, so I am being extravagant and doing it all 100%. For most of you, if you review this progression of Engineering thought, what I am saying is that it is not cost effective to do it all, unless money is no object.

If you are flush, rich, then yes go for it. Depending on your equipment here are the advantages:
Yes: It does charge about 40-50% faster.
Yes: You can get about 50-60% more out of it.
It does not have a memory problem, you cycle it in any state or range without harming it like in normal AGM batteries where you have to run it to Boost cycle them properly.. Lithium does not have this range of cycle problem.
It has near nil internal resistance and does accept more solar where depending on the size of the AGM battery they will burn from 1 to 3 amps of solar input to excited them enough to begin accepting a charge.. Lithium takes a lot more of the Solar Input having a very low internal resistance.

But it is expensive to do it right. And not to do it right and a cheap nasty Lithium battery slam in place, is not cost effective and will only last as long as normal AGM batteries but at about four times the cost..

Good luck to all of you, I am gone and will not add any more to this Thread..

Kind regards to all.

[Helia 44]

One last, last thing....

These Professional Grade Lithium Batteries are bigger cells and so on in a powder coated armoured case, with BMS on board, and multi battery Active Balancing and a whole lot of other management equipment.. They COULD last 15-20 years.. However: I am down rating them to Ten years as they will be in a warmer environment. I will insulate and put extra blowers in the Port engine room, but they will STILL be in a warmer environment. I will even lift the engine room hatch when I shut down..

Experience has shown us with 500 plus units of multiple Lithium battery installations in the field up to 900 AH, that the warmer environment shortens their life. Like maybe 1500-2000 Lithium batteries running.. Even in north Australia like Darwin, where it is a lot hotter in the Tropical zone, the Lithium batteries do not last as long. There will be a lower life expectancy if you put Lithium in the engine room, better to remotely locate them.. Terrible to put them in the engine bay of a vehicle for instance, and would void most warranties..

I am gone, will not add to this Thread, nor respond to any more posts.. I did this undertaking to return something to this Cruiser Forum from my Professional Experience in Lithium conversions, free of charge, in your best interests..

Goodbye...

[Supercat568]

LiPo batteries are coming down in price faster than a drunken sailor will wreck a boat. I'd estimate they've reduced by half in the last two years. I'm not sure about the big guys used on boats however, but they have to be following the trend a little at least. Does the factor of near term drastic price reduction change your outlook at all? Or am i wrong on near term pricing?
Plus, what about the Lithuanians? Do you think this might be a blow to their economy?��

[Djarraluda]

Out of interest, you continually refer to a "Professional Engineering study" and as such, I am presuming you are RPEQ, or at least CPEng. I have not found such an appropriate comparison analysis previously, so wonder if the paper published somewhere so I could study the details please?
As a Professional Consulting Engineer myself, I regularly condemn candidates for assertions rather than fact and am technically curious at the inputs and conclusions - it is a bad habit perhaps, but after all these years it is one that is ingrained.
Many thanks,
Roger